Printing an array within double quotes

Question

my @a = (1,2,3,4,5);

print @a;      #output: 12345

print \"\\n\";

print \"@a\";    #output: 1 2 3 4 5

Printing an array by putting its name with

Answer 1

When Perl sees an array in an interpolated string, it rewrites it using join:

print "@array";

becomes

print join($" => @array);

by default, the value of $" is equal to a single space.

You can configure this behavior by localizing a change to $"

print "@array";     # '1 2 3 4 5'
{
    local $" = '';  # "
    print "@array"; # '12345'
}
print "@array";     # '1 2 3 4 5' 

You can see how Perl rewrites your interpolated strings using the -q option of the core B::Deparse module:

$ perl -MO=Deparse,-q -e 'print "@array"'
print join($", @array);
-e syntax OK